Oooh my blood fairly boiled yesterday, it really did.  Well ok, not really.  At least not in the sense that my blood reached 100 degrees Celsius, more in the sense that I was shouting pointlessly at the radio.  Why?  Because the Jeremy Vine radio show on BBC Radio 2 had a piece about the Royal College of Obstetricians and Gynaecologists’ (RCOG) paper that suggested that pregnant women should avoid exposure to certain everyday chemicals.  Now, I will get to that issue in a minute, but first let’s talk about the item on the radio programme.

It started with lots of talk of avoiding ‘chemicals’, and Jeremy asking if listeners made a habit of avoiding them.  Now as I discussed in a previous post, chemicals are all around us.  Because everything is a chemical.  Water is a chemical, so is oxygen, so is baking soda, so is vitamin C.  Frankly, anyone who thinks they avoid chemicals doesn’t understand what they are.  Now, this was BBC Radio 2.  If someone had mixed up the words less and fewer there would be hell to pay, but apparently no such rigour applies to use of scientific terms.

The next irritation was the choice of guests. Hazel Courteney was pitched against Adam Hart-Davis.  Courteney is a journalist specialising in alternative health (alternative treatments being, by definition, the ones which have not been proven effective using scientific methods; the ones which have been proven effective are, you know, medicine).  She was described on the show as a ‘health journalist’ but as far as I can tell, she has no scientific or medical qualifications.  Hart-Davis, on the other hand, has a PhD in organometallic chemistry.  Is this balanced?  Just because two people appear to have opposing viewpoints, should they necessarily be given equal weight?  It happens all too often with scientific and medical issues, presumably because it’s perceived as being more entertaining, but it’s worrisome because it gives the impression to the listener that the two people are equally qualified and knowledgeable.

So were they?  Let’s get on to some of the things Courteney said.  I have forced myself to listen again on iPlayer to make absolutely sure I’m not misquoting.  I hope everyone appreciates the sacrifice.  My blood pressure may never be the same again.

“The average person absorbs into their bloodstream alone about 14 kg of toxins annually through their skin.”

I can find no evidence for this claim, and have no idea where it comes from (update: I later went on to write a blog post for the Ask for Evidence campaign on this question).  Skin is actually pretty impermeable stuff.  If it weren’t we’d all be in a whole heap of trouble every time we had a bath.  Never mind chemicals, you’d turn into a water-filled balloon.  There are some chemicals that can be absorbed through skin, but not many in the grand scheme of things.  Nicotine is one, that’s how nicotine patches work, but that’s fairly easily avoided.  There are herbicides and pesticides that can be absorbed this way, but unless you’re spraying with them and utterly failing to follow health and safety protocols (there’s a reason people wear gloves and masks), you’re not going to come into contact with anything at all significant.  Even if you’re spraying without the proper safety gear, you’re not going to absorb 14 kg unless you take a bath in the stuff.  Stop press: pregnant women shouldn’t bathe in herbicide.

“[ammonia] is in toilet cleaners, window cleaners.  It’s also in hair dyes.”

One of her less outlandish claims, but I include it because first of all, not really.  Most bleaches sold in this country are based on hypochlorite, not ammonia.  And the majority of window cleaners on sale are little more than some detergent and vinegar.  Ammonia might once have been in hair dye, but a lot of them are marketed as ‘no ammonia’ these days, mainly because consumers hate the smell.  Ammonia really stinks.  Secondly, it’s pretty irrelevant.  Yes ammonia is toxic, but it’s also extremely volatile.  In a well-ventilated area it will quickly disperse and you’ll barely notice it.  The small quantities you might inhale aren’t harmful because the body actually has a mechanism to prevent ammonia build up (because it’s a by-product of breaking down protein, which we all do whether we know it or not).  Yes if you lock yourself in an enclosed space with a large quantity of ammonia gas, it will irritate your eyes and lungs.  But, you know, don’t do that.

“Oestrogen is a builder, and therefore the more hormone-disrupting toxins you have in your body, the more oestrogen-like compounds you will make, and they can migrate to fatty tissues such as your breasts, and that’s one of the major contributing factors to breast cancer today.”

Oestrogen is a builder?  What, like Bob?  I’m not even sure what she means by that.  Oestrogens promote the development of female secondary sexual characteristics, such as breasts, and there are legitimate concerns about certain substances in the environment causing fertility problems particularly for men, who under normal circumstances wouldn’t be exposed to oestrogen.  But a major contributing factor to breast cancer?  Well, according to the NHS choices website, the major contributing factors are age and family history.  Way down the list is: “Your risk of developing breast cancer may rise slightly with the amount of oestrogen your body is exposed to.”  Note the word ‘slightly’.  Not ‘significantly’.  And using combined contraceptives, hormone replacement therapy or just being a woman will expose you to a lot more oestrogen than you’ll ever seen from your environment.  In fact, being pregnant actually reduces your exposure to this hormone, because its production is disrupted during pregnancy.  So in this respect by being pregnant you’re doing yourself a big health favour.  That’s something comforting to remember when you’re throwing up and nursing your swollen ankles.

“Clingfilms (that) contain PCBs”

PCB stands for polychlorinated biphenyl.  They were once used as plasticisers, but mostly in paints and cements.  They’re definitely toxic and they’ve been linked to cancer.  But PCB production was banned by the United States Congress in 1979 and by the Stockholm Convention on Persistent Organic Pollutants in 2001.  If you have clingfilm that contains PCBs, I’m curious to know where you bought it.

“If you have a takeaway meal, and you microwave it in a plastic container, that releases large amounts of oestrogen-altering chemicals.”

Now, there is ongoing debate about a substance used in plastics called bisphenol A (BPA).  It does exhibit hormone-like properties, it might be released when certain plastics are heated, and the European Union, Canada, and the United States have consequently banned BPA use in baby bottles.  Baby bottles are a specific case though; you have to bear in mind that a lot of people sterilise them by heating to high temperatures for extended periods of time.  The Food Standard Agency’s position is that “current level of consumer exposure to BPA from food contact materials does not represent a food safety risk for consumers”, that the science shows that it only has “weak oestrogenic effects” and that “effects [are] generally seen at high doses”.  Genuine concern aside, I still take issue with Courteney’s use of the words “large amounts”.  The Plastic Materials and Articles in Contact with Food (England) Regulations 2009 (snappy title) permit the use of BPA provided that no more than 6 mg per kg migrates into food.  Let’s say we have a plastic container that weighs 100 g (that would be quite a large tub), that means that at the very top end we’re talking about 0.0006 g of BPA getting into your food.  And it’s highly likely to be far less than that in reality.  That’s not a ‘large amount’.  Still I will grudgingly admit that she may have a bit of a point here: if all this worries you, put your food into a glass container before you heat it.

“If your shampoo or body lotion has sodium laureth sulfate or sodium lauryl sulfate these are detergents and emulsifiers used in thousands of cosmetics, um, when you ingest them they can have a really negative effect” followed a little later by, “it’s heavily linked to cancers.  There’s plenty of research to show that it does accumulate.  SLS does accumulate in the eyes, the heart, the liver, the brain.  It can be come quite toxic to the liver.  And the more toxins you have in your liver the angrier you become.”

Mmm.  So, better not eat your shampoo or shower gel then.  Why is she talking about ‘ingesting’ substances which aren’t generally eaten?  Sodium lauryl sulfate and sodium laureth sulfate are detergents, that bit’s true, but they’ve been used for an awfully long time and there really is no evidence either is horribly harmful.  Both have been tested extremely rigorously, and have been consistently shown have no causal link with cancer.  It’s just possible they might cause skin irritation in sensitive individuals, that’s about it.  Although you know, perhaps it is better to be safe than sorry.  Wouldn’t want to risk an angry liver.

“When you ingest chemicals, say in food, your saliva and stomach acid help break them down and you excrete them.  But when you’re absorbing all these toxins through your skin they’re absorbed straight into your bloodstream and therefore, you know, can have a very negative impact over time.”

Er, what?  Just, what?  This makes no sense.  She’s saying that it’s safer to eat these substances than put them on your skin?  But didn’t she just say that sodium laurel sulfate was particularly harmful if ingested?  Make your mind up.

All this nonsense in 18 minutes.  Impressive, no?  Poor Adam Hart-Davis did try and argue against some of it, but I fear he lost the battle.  I’m not sure he was expecting quite such an onslaught.  Poor man.

I should make brief mention of the thing that started all this in the first place.  The Royal College of Obstetricians and Gynaecologists (RCOG) released a Scientific Impact Paper titled “Chemical Exposure During Pregnancy: Dealing with Potential, but Unproven, Risks to Child Health” (I have linked to the actual, original, paper, not a news report).  Now, the clue is in the title.  Unproven risks.  Essentially they are commenting on the, very small, possibility that a pregnant woman’s exposure to a variety of environmental toxins might combine to create a harmful effect to the baby.  They suggest using fresh food rather than processed (shock), as well as some less practical tactics such as reducing the use of foods/beverages in cans/plastic containers (perhaps women should carry their water supplies in a traditional oilskin bag?) and minimising the use of personal care products such as moisturisers and shower gels (presumably it would be much healthier to just stop washing).

In fairness, the original document does include statements that balance things a bit.  It comments that: “Under normal lifestyle and dietary conditions, the level of exposure of most women to individual environmental chemicals will probably pose minimal risk to the developing fetus/baby.”  And, “it is unlikely that any of these exposures are truly harmful for most babies”.

Unfortunately the media didn’t initially present that side of it.  We had multiple headlines such as: “Pregnant women warned over household product chemicals” and at the more alarmist end of the spectrum: “Pregnant women told to avoid painting the nursery, buying new furniture or going near non-stick FRYING PANS” (sic).  Fortunately lots of other, more sensible, people immediately started writing about the issue and now a search for this particular news item brings up lots of articles putting the other side, for example: “New advice to pregnant women is unhelpful and confusing, say critics“.  I don’t think there’s any need for me to say it all again.  But if you are pregnant right now, my advice (as someone who’s recently been through it) would be to try not to worry about it, put your feet up and have a biscuit.  Pregnancy is difficult enough as it is.